Preventative war has a long history in international politics, but until it became an instrumental part of the 'Bush Doctrine', it was mostly overlooked. We know that there have been preventative wars throughout history, but the motivations behind them have remained elusive. Because of the relatively little attention focused on preventative action, there are many crucial questions that remain unanswered. What exactly constitutes preventative action? What differentiates preventative action from pre-emptive action? Are there significant differences between preventative strikes and full-on preventative wars? What is the relationship of preventive action to traditional concepts of deterrence, compellence, and international law? Finally, and most important, why do states initiate preventative action? Ultimately, the best avenue for understanding decisions to initiate preventative action is through a close examination of the individual leader responsible for such decisions. The theory of preventative action presented in this book is based upon the beliefs, values, and perceptions of leaders. Israel's strike on Iraq's nuclear reactor, 1981; American preventive war planning, 1946-1954; Indian preventative war planning, 1982-2002; and America's war against Iraq, 2003. In each instance, preventative action was seriously considered, and yet it only occurred in three of the five cases. In the end, each case provides further evidence that individual leadership matters, and nowhere more so than in decisions involving preventative war.

Political scientists designing experiments often face the question of how abstract or detailed their experimental stimuli should be. Typically, this question is framed in terms of tradeoffs relating to experimental control and generalizability: the more context introduced into studies, the less control, and the more difficulty generalizing the results. Yet, we have reason to question this tradeoff, and there is relatively little systematic evidence to rely on when calibrating the degree of abstraction in studies. We make two contributions. First, we provide a theoretical framework which identifies and considers the consequences of three dimensions of abstraction in experimental design: situational hypotheticality, actor identity, and contextual detail. Second, we field a range of survey experiments, varying these levels of abstraction. We find that situational hypotheticality does not substantively change experimental results, but increased contextual detail dampens treatment effects and the salience of actor identities moderates results in specific situations.